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New Member

SG300-20 - Problems with Forwarding and Learning MACs until Write

I have an SG300-20 and started having problems a few weeks ago.  Primarily the problem is related to rebooting systems, waking systems from sleep, or any other activity such as speed/duplex changes on the host that cause the host NIC to cycle.  Regardless of how the host NIC "goes down", when the host NIC "turns up" it shows connected on the host and switch, but the SG300 refuses to learn the MAC.  The only remedy seems to be the write command.  Immediately after the write command is issued there is delay from 0 to a few seconds, then L2 connectivity returns.

Also, a new problem cropped-up during testing after changing the mode to "route."  If I reload the switch it stops forwarding all traffic until a write command is issued.

Anyone see these symptoms and have a solution?

Thanks,

Jeff

25 REPLIES
Green

SG300-20 - Problems with Forwarding and Learning MACs until Writ

Hi Jeff, first, what software version do you use?

Seconds, have you looked at any of the Energy Efficient Ethernet settings? (You may want to disable them).

-Tom
Please mark answered for helpful posts

-Tom Please mark answered for helpful posts http://blogs.cisco.com/smallbusiness/
New Member

SG300-20 - Problems with Forwarding and Learning MACs until Writ

Hi Tom,

Thanks for your response.

I have tested both the previous release (1.3.0.36 I believe) as well as the most recent release 1.3.5.58.  Also, I have tried just about every EEE and Green-Ethernet setting possible, including disabling EEE and GreenEth.

Any other ideas?

Thanks,

Jeff

Green

SG300-20 - Problems with Forwarding and Learning MACs until Writ

Hi Jeff, it may be spanning tree related or it could be software related.

Does the switch have any config on it in particular?

Globally disable spanning tree and see what happens.  Do you have a second switch around? May be test with a completely default switch and see if the behavior follows.

-Tom
Please mark answered for helpful posts

-Tom Please mark answered for helpful posts http://blogs.cisco.com/smallbusiness/
New Member

SG300-20 - Problems with Forwarding and Learning MACs until Writ

Hi Tom,

Thanks for the suggestion.

I have tried disabling all of the following at one time or another:

-CDP

-LLDP

-Bonjour

-EEE

-Green-Ethernet

-SmartPort Global

-SmartPort on interface

I have also tried the following:

-STP Portfast

-Downgrading firmware

-Upgrading firmware

-Factory reset

-Hard setting speed and duplex (1000F, 100F, 100H)

-Autonegotiation (100F, 100F, 100H, slave, master)

-With Flowcontrol

-Without Flowcontrol

-MDIX on

-MDIX off

-Router mode

-Switch mode

-with NTP configured

-without NTP configured

-with Syslog configured

-without syslog configured

-with only a basic config after reset:  one vlan with the mgmnt address and one access port (and also with two access ports)

Any other ideas?

Thanks,

Jeff

New Member

SG300-20 - Problems with Forwarding and Learning MACs until Writ

Forgot to mention....

Also have tried disabling STP - no luck.

New Member

Hi Jeff,sorry for my very

Hi Jeff,

sorry for my very late answer,

my problem is solved - i got a new sg300 from cisco and sold it on ebay....

New Member

SG300-20 - Problems with Forwarding and Learning MACs until Writ

Another symptom I saw again, but only once in past testing is that after a reload, all ports seem to bounce up and down continuously, even though the port lights do not show up/down status.  I have only seen this twice, and I get continuous logs to the console when it happens.  Again, none of the ports learn MACs and only a write command seems to correct it.

It sounds very similar to the following case: 

https://supportforums.cisco.com/message/3959254#3959254

In my opinion this switch has a hardware problem.  How do I get it swapped under warranty?

Thanks,

Jeff

Green

SG300-20 - Problems with Forwarding and Learning MACs until Writ

Hi Jeff, from the US 1.866.606.1866

Here's a list by country

http://www.cisco.com/en/US/support/tsd_cisco_small_business_support_center_contacts.html

-Tom
Please mark answered for helpful posts

-Tom Please mark answered for helpful posts http://blogs.cisco.com/smallbusiness/
New Member

SG300-20 - Problems with Forwarding and Learning MACs until Writ

Hi Jeff,

is your case solved? I have still the same problem. After powering on the switch only a write mem command via the serial console brings it to work. I'm running the latest firmware and bootloader (FW 1.3.5.58) and made already factory reset. Were your problems hardware affected?

regards, Christian

New Member

SG300-20 - Problems with Forwarding and Learning MACs until Writ

Christian,

No solution yet.  And I'm stuck in Cisco's support hell....there bussines support is located in China (UTC+8) which means only one email exchange a day.  At this rate we'll be running IPv8 before it's fixed...

Will post if I get a fix.

Thanks,

Jeff

New Member

SG300-20 - Problems with Forwarding and Learning MACs until Writ

Hi Jeff,

thanks for your quick response. So we have to wait... Thanks so far!

Green

SG300-20 - Problems with Forwarding and Learning MACs until Writ

Hi Jeff and Christian, can you give exact step to recreate? I'm having problems to recreate the problem.

Is this dependent on a certain network card or device?

Please provide the exact step by step how you can create this problem and if it is localized to any 1 type of connection or all connections.

-Tom
Please mark answered for helpful posts

-Tom Please mark answered for helpful posts http://blogs.cisco.com/smallbusiness/
New Member

SG300-20 - Problems with Forwarding and Learning MACs until Writ

Hi Tom,

Thanks for your response.

Steps to recreate my issue:

1.  Factory reset SG300-20

2.  Ping from Host A to Host B and/or vice versa

3.  Ping unsuccessful until “write” command issued

Notes:

- Upon issuing write command, connectivity is either immediate or up to a few seconds later

- Until a write command is issued, the “sh mac address-table” command shows no MACs except that of the switch itself on port 0

Also, I see these same symptoms for a host if the NIC on the host transitions (down/up).  Upon a transition the switch does not learn the MAC address and the “sh mac address-table” command shows no MAC for the host NIC that transitioned.

BTW - I appreciate your help and quick responses and I did open a TAC ticket.  However, it is frustrating that the TAC resource is UTC+8, only provides support during their work hours, and does not provide a local phone number.

Thanks,

Jeff 

Green

SG300-20 - Problems with Forwarding and Learning MACs until Writ

Jeff, I can't recreate this.

switch0d8210#set system mode switch                                  

Changing the switch working mode will *delete* the startup configuration file                                                                            

and reset the device right after that. It is highly recommended that you will                                                                            

backup it before changing the mode, continue ? (Y/N)[N] Y                                                        

switch0d8210#10-Oct-2013 17:19:08 %FILE-I-DELETE: File Delete - file URL flash:/                                                                               

/startup-config              

switch0d8210#reload                  

You haven't saved your changes. Are you sure you want to continue ? (Y/N)[N] Res                                                                               

etting local unit                

**************************************************                                                 

*****************  SYSTEM                        

Boot1 Checksum Test...............................PASS                                                     

Boot2 Checksum Test...............................PASS                                                     

Flash Image Validation Test.......................PASS                                                    

BOOT Software Version 1.3.5.06 Built  21-Jul-2013  15:12:10                                                          

                    #                               #                                                    

                   ###                             ###                                                     

                   ###                             ###                                                     

                   ###                             ###                                                     

            #      ###      #               #      ###      #                                                            

           ###     ###     ###             ###     ###     ###                                                             

    #      ###     ###     ###      #      ###     ###     ###      #                                                                    

   ###     ###     ###     ###     ###                                        

   ###     ###     ###     ###     ###     ###     ###     ###     ###                                                                     

   ###     ###     ###     ###     ###     ###     ###     ###     ###                                                                     

    #       #      ###      #       #       #      ###      #       #                                                                    

                   ###                             ###                                                     

                   ###                             ###                                                     

                    #                               #                                                    

            #######   ###    #######       #######      #####                                                            

          #########   ###   ###    ##    #########    #########                                                              

         ###          ###    ####       ###          ###     ###                                                               

         ###          ###      ###      ###          ###     ###                                                               

         ###          ###       ####    ###          ###     ###                                                               

          #########   ###   ##    ###    #########    #########                                                              

            #######   ###    #######       #######      #####                                                            

Networking device with Marvell ARM CPU core. 128 MByte SDRAM.                                                            

I-Cache 16 KB. D-Cache 16 KB. L2 Cache 256 KB. Cache Enabled.                                                            

MAC Address   :  00:26:0b:0d:82:10.                                  

Autoboot in 2 seconds - press RETURN or Esc. to abort and enter prom.                                                                    

Preparing to decompress...                         

100%    

Decompressing SW from image-1                            

100%    

OK 

Running from RAM...                  

GPIO ID is 3           

Module type is 10                

Device ID 0xdff411ab                   

*********************************************************************                                                                    

*** Running  SW  Ver. 1.3.5.58  Date  10-Oct-2013  Time  17:15:41 ***                                                                    

*********************************************************************                                                                    

HW version is V01                

Base Mac address is: 00:26:0b:0d:82:10                                     

Dram size is  : 128M bytes                         

Dram first block size is  : 102912K bytes                                        

Dram first PTR is  : 0x1780000                             

Dram second block size is  : 4096K bytes                                       

Dram second PTR is  : 0x7C00000                              

Flash size is: 16M                 

................................................................................                                                                               

................................................................................                                                                               

................................................................................                                                                               

.....10-Oct-2013 17:15:44 %CDB-I-LOADCONFIG: Loading running configuration.                                                                          

10-Oct-2013 17:15:44 %CDB-I-LOADCONFIG: Loading startup configuration.                                                                     

Device configuration:                    

Slot 1 - SG300-28P                 

Device 0: GT_98DX3025 (AlleyCat)                               

------------------------------------                                   

-- Unit Standalone                --                                   

------------------------------------                                   

Tapi Version: v1.9.6                   

Core Version: v1.9.6                   

10-Oct-2013 17:16:20 %INIT-I-InitCompleted: Initialization task is completed                                                                           

Detected speed: 115200                     

10-Oct-2013 17:16:34 %Entity-I-SEND-ENT-CONF-CHANGE-TRAP: entity configuration c                                                                               

hange trap.          

10-Oct-2013 17:16:34 %SNMP-I-CDBITEMSNUM: Number of running configuration items                                                                              

loaded: 0        

10-Oct-2013 17:16:34 %SNMP-I-CDBITEMSNUM: Number of startup configuration items                                                                              

loaded: 0        

The SSH Server is generating a default RSA key.                                              

This may take a few minutes, depending on the key size.                                                      

10-Oct-2013 17:16:35 %Environment-I-FAN-STAT-CHNG: FAN# 1 status changed - opera                                                                               

tional.      

The SSH Server is generating a default DSA key.                                              

This may take a few minutes, depending on the key size.                                                      

10-Oct-2013 17:17:20 %SYSLOG-N-LOGGING:                                      

The SSH Client is generating a default RSA key.  

User Name:cisco              

Password:

This may take a few minutes, depending on the key size.e default settings. Please change the passwor         

The SSH Client is generating a default DSA key.                     

d for better protection

This may take a few minutes, depending on the key size.                                                      

10-Oct-2013 17:18:16 %SSL-I-SSLCTASK: Starting autogeneration of self-signed cer                          

Aging time is 300 sec                    

switchb2

tificate - 1024 bitsitchb29140#wr mem  

Generating RSA private key, 1024 bit long modulus Port       Type                                

10-Oct-2013 17:18:24 %SSL-I-SSLCTASK: Autogeneration of self-signed certificate                                        

   1       e0:5f:b9:b2:91:40       0

was successfully completed                         

Generating RSA private key, 1024 bit long modulush mac address-tab                             

User Name:         

press ENTER key to retry authentication

User Name:

Detected speed: 115200

User Name:cisco

Password:*****

Please change your password from the default settings. Please change the passwor

d for better protection of your network. Do you want to change the password (Y/N

)[Y] ?N

switch0d8210#show mac address-table

Aging time is 300 sec

  Vlan        Mac Address         Port       Type

-------- --------------------- ---------- ----------

   1       00:26:0b:0d:82:10       0         self

   1       64:31:50:1c:50:d3      gi3      dynamic

   1       d0:67:e5:56:14:32      gi2      dynamic

switch0d8210#

-Tom
Please mark answered for helpful posts

-Tom Please mark answered for helpful posts http://blogs.cisco.com/smallbusiness/
Green

SG300-20 - Problems with Forwarding and Learning MACs until Writ

Jeff, I tried a second time as well. I had noticed during my first time I hit "enter" several times because I like to watch my screen scroll. But regardless, it made no difference for me.

switch0d8210#reload------- ----------

You haven't saved your changes. Are you sure you want to continue ? (Y/N)[N] Yf:b9:b2:91:40       0         self                                           

This command will reset the whole system and disconnect your current session. Dotal number of entries: 0                         

  VLAN    Interface     IP

you want to continue ? (Y/N)[N] Ystatus                           

Shutting down ...                

Shutting down ...--------- -------

Shutting down ...---------- ------

Resetting local unit                   

**************************************************9140#            

switchb29140#delete startup-con

*****************  SYSTEM          

Delete startu

Boot1 Checksum Test........................        

switchb29140#            

                    #                               #reset the device right after that. It is highly recom

                   ###                             ###                                         

backup it b

                   ###                             ###                                               

switc

                   ###                             ###b29140#reload                  

You haven't saved you

            #      ###      #               #      ###      #                                                            

           ###     ###     ###             ###     ###     ###nnect                                                       

   ###     ###     ###     ###     ###     ###     ###     ###     ###..PASS                                                     

Flash Im

    #       #      ###      #       #       #      ###      #       #                             

BOOT Software Version 1.2.0.12 Buil

                   ###                             ###                           

                    #  

                   ###                             ###                          

                   ###   

                    #                               #                           

   ###     ###     ###     ###  

          #########   ###   ##    ###    #########    #########                                          

   ###     ###    

            #######   ###    #######       #######      #####                                                          

Networking device with Marvell ARM CPU core. 128 MByte SDRAM. ##                                                         

100%    

Decompressing SW from image-1                            

100%

OK 

Running from RAM...#######       #####

GPIO ID is 3           

Module type is 10                

Device ID 0xdff411ab    #########   ###

*********************************************************************                            

         ###          ###    ####     

*** Running  SW  Ver. 1.3.5.58  Date  10-Oct-2013  Time  17:15:41 ***                  

         ###          ###      ###      ###     

*****************************************************************            

Dram first PTR is  : 0x1780000##    #######       #######  

Dram second block size is  : 4096K bytes                           

Networki

Dram second PTR is  : 0x7C00000ore. 256 MByte SDRAM.         

Flash size is: 16M                 

................................................................................                                                       

MAC Address   :  e0:5

................................................................................RETURN or Esc. to abort and enter prom.                                        

................................................................................

100%    

Decompressing SW from image-2                            

100%   

------------------------------------

HW version is V01                

Tapi Version: v1.9.6e0:5f:b9:b2:91:40  

Core Version: v1.9.6             

Dram

10-Oct-2013 17:16:18 %INIT-I-InitCompleted: Initialization task is completed08896K bytes                                        

Dram first PTR is  : 0

10-Oct-2013 17:16:33 %Entity-I-SEND-ENT-CONF-CHANGE-TRAP: entity 4096K bytes                                       

Device 0: GT

This may take a few minutes, depending on the key size.------------------------------                        

10-Oct-2013 17:16:34 %Environment-I-FAN-STAT-CHNG: FAN# 1 status changed - opera  

------------------------------------                                   

19

tional.2 17:57

The SSH Server is generating a default DSA key.configuration c                               

This may take a few minutes, depending on the key size.rap.          

19-Jul-2012 17:57:51 %INIT-I-InitComple

The SSH Client is generating a default DSA key.ode.                                          

This may take a few minutes, depending on the key size.CK-CFG-CHNG: Configuration changed: chain             

10-Oct-2013 17:18:23 %SSL-I-SSLCTASK: Starting autogeneration of self-signed cer..............................PASS                                             

tificate - 1024 bitssum Test............

Generating RSA private key, 1024 bit long modulus                         

Flash Image Validatio

10-Oct-2013 17:18:31 %SSL-I-SSLCTASK: Autogeneration of self-signed certificate      

BOOT Software Version 1.3.5.06 Built  21-Jul-2013  15:             

was successfully co                 

switch0d8210#           

User Name:        ##

Detected speed: 115200       ###           

User Name:cisco              

Password:*****       #     

Please change your password from the default settings. Please change the passwor                    

           ###     ###     ###             ###     ###   

d for better protection of your network. Do you want to change the password (Y/N     ###     ###      #      ###     ###     ###      #                        

)[Y] ?N      

switch0d8210#show mac address-table    ###     ###     ###     ###   

Aging time is 300 sec   ###              

  Vlan        Mac Address         Port       Type   

switch0d8210#     #      #

switch0d8210#10-Oct-2013 17:19:08 %LINK-W-Down:  gi3                                

10-Oct-2013 17:19:08 %LINK-W-Down:  Vlan 1                                         

switch0d8210#          ###

switch0d8210#show mac address-table                                  

Aging time is 300 sec              #     

  Vlan        Mac Address         Port       Type                           

   1       64:31:50:1c:50:d3      gi3      dynamic

switch0d8210#10-Oct-2013 17:19:16 %LINK-I-Up:  gi3, aggregated (1)

10-Oct-2013 17:19:16 %LINK-I-Up:  Vlan 1, aggregated (1)

10-Oct-2013 17:19:21 %STP-W-PORTSTATUS: gi3: STP status Forwarding, aggregated (

1)

10-Oct-2013 17:19:31 %LINK-W-Down:  gi3, aggregated (1)

10-Oct-2013 17:19:31 %LINK-W-Down:  Vlan 1, aggregated (1)

10-Oct-2013 17:19:36 %LINK-I-Up:  gi4

10-Oct-2013 17:19:36 %LINK-I-Up:  Vlan 1, aggregated (1)

10-Oct-2013 17:19:41 %STP-W-PORTSTATUS: gi4: STP status Forwarding

switch0d8210#

switch0d8210#show mac address-table

Aging time is 300 sec

  Vlan        Mac Address         Port       Type

-------- --------------------- ---------- ----------

   1       00:26:0b:0d:82:10       0         self

   1       64:31:50:1c:50:d3      gi4      dynamic

switch0d8210#10-Oct-2013 17:19:50 %LINK-W-Down:  gi4

10-Oct-2013 17:20:53 %INIT-I-Startup: Warm Startup

switch0d8210#

switch0d8210#show mac address-table

Aging time is 300 sec

  Vlan        Mac Address         Port       Type

-------- --------------------- ---------- ----------

   1       00:26:0b:0d:82:10       0         self

switch0d8210#

-Tom
Please mark answered for helpful posts

-Tom Please mark answered for helpful posts http://blogs.cisco.com/smallbusiness/
New Member

SG300-20 - Problems with Forwarding and Learning MACs until Writ

Tom,

I understand that you cannot recreate the problem - I really didn't think you would be able too, not with a working switch.  If you were able to recreate this problem your Cisco TAC phones would light up like a Chrismas tree, because noone likes a switch that won't switch, and a fix would be issued.

My switch however, does show this problem and since we are both using the same model switch and firmware version, there must be a defect with my switch.  The reason I say this is because, given a switch, any switch, with the latest firmware and a factory reset, when the switch boots, it should learn MACs and forward traffic without having to save the config - learning MACs and forwarding traffic is what a switch does.  But for some reason I feel that you and TAC are missing this quintessential point:  MY SWITCH DOES'T ALWAYS SWITCH.

Because my switch has this problem (not switching) I would expect Cisco to replace/repair it under warranty.  I have told TAC of this expectation, but they insist on troubleshooting (turn on STP, turn off STP, etc) rather than realize that a switch that won't learn MACs isn't a switch and that it needs to be replaced/repaired.

Now I will ask you the same question I have asked TAC, twice, how do I get a replacment or a repair?

Thanks,

Jeff

New Member

SG300-20 - Problems with Forwarding and Learning MACs until Writ

Tom,

Sorry, for some reason I thought you were with Cisco Support.  Not sure why I thought that, but thanks for trying to help and sorry I vented on you - I really thought you were Cisco Support.

Sorry,

Jeff

Silver

SG300-20 - Problems with Forwarding and Learning MACs until Writ

Hi Jeff,

Did you receive a Service Request number when you called the Cisco Small Business Support Center (http://www.cisco.com/en/US/support/tsd_cisco_small_business_support_center_contacts.html)?

If so, can you private message me the number and I will check the status for you.

Regards,
Cindy Toy
Cisco Small Business Community Manager
for Cisco Small Business Products
www.cisco.com/go/smallbizsupport
twitter: CiscoSBsupport

Regards, Cindy If my response answered your question, please mark the response as answered. Thank you!
New Member

SG300-20 - Problems with Forwarding and Learning MACs until Writ

Problem FIXED!!!!

After getting no support from Cisco except three emails with basic troubleshooting garbage, and having a ticket open with their TAC for more than eight days,  I bought a new switch and it works perfectly.  Unfortunately for Cisco it is not a Cisco switch.

I bought a N.E.T.G.E.A.R  GS728TP !!!!  And it solved my problem with the Cisco switch.  The GS728 learns MAC addresses and switches, but the Cisco switch does not switch - go figure....

New Member

SG300-20 - Problems with Forwarding and Learning MACs until Writ

Have the same problem. Switch works only after "write" command.

Also I'm running the latest firmware and bootloader.

It's too bad that there no solution with this switches. I have 12 of them.

New Member

Re: SG300-20 - Problems with Forwarding and Learning MACs until

Hi Alexandr,
Do You have this issue with all of your switches?
What is after you made a write command, how long will it last till the Problem comes again?
In my Case the switch did work after Write command but with poor performance and after a few hours the problem came again...


Sent from Cisco Technical Support iPad App

New Member

Re: SG300-20 - Problems with Forwarding and Learning MACs until

Hi Christian!

Sorry for late response.

For me it's hard identify problem because we installed switches in branches in 150 miles or more from HO.

Problem appears after switch restarts. And every morning. Maybe at night there are no power in branches, maybe not.

My network topology in branch:

Internet cable -> Cisco 881 Router -> Cisco SG300 Switch. Pretty simple.

Router plugged into 17th port on switch. And mostly it has not problem with mac learning.

So I can connect to switch from HO via SSH or HTTP and make "write" command.

Sometimes switch become working after hour or more after restart.


For today problem appeared again and I had no connection to switch.

Router was fine and it showed that fe0 and vlan are up. Cable is good and plugged properly.

After 1 hour switch become reachable. When I connect to switch I saw that it learned only router's mac address (Port 17). I made "write" command and it learned other mac addresses of my PCs in the network.


New Member

I'm planning to get in touch

I'm planning to get in touch with Cisco sometime today or tomorrow but has anyone else seen this as well?  I put this switch into use early January of 2014.  I'd say this probably started showing up back in July or August of 2014.  Various firmware upgrades/downgrades have not worked.  I can repeatedly kill the network connection on a port and then try to bring the device back up but it will not learn/show the MAC address for that port until I issue the write command.  I even cleared the entire table once and all devices lost network access until I was forced to reboot it.  I tried various ping/ARP commands to force try to get the switch to pick up and learn a MAC address before rebooting but it just wouldn't work.  Disabled all Green/EEE settings as well as SmartPort.  I've got a collection of configurations beginning in January when there was no issue like this and tried those settings as well.

New Member

Well, after sending Cisco

It looks like I'll be taking the same route as Jeff and purchasing a Netgear managed switch to replace my SG300-20.

Hi Jim,I am really sorry to

Hi Jim,

I am really sorry to hear that but I must admit that this either hardware related issue or very specific to the whole network setup. I have never seen such a problem before unless there was a loop.

Regards,

Aleksandra

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